| 1. |
- Bechshoft, Thea, et al.
(författare)
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Developing a new research tool for use in free-ranging cetaceans : recovering cortisol from harbour porpoise skin
- 2015
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Ingår i: Conservation Physiology. - 2051-1434. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- We developed a chemical analytical procedure for sampling, extracting and determining epidermal skin cortisol concentrations (SCCs) in the harbour porpoise (Phocoena phocoena) using gas chromatography–tandem mass spectrometry. In brief, this involved a pressurized liquid extraction with a two-step solid-phase clean-up. A derivatization step was conducted prior to detection. To evaluate the new assay, cortisol was analysed in three different sample types obtained from four harbour porpoises: skin plates, dorsal fin skin plugs (with and without lidocaine) and epidermal scrapes. Skin cortisol concentrations could be measured using the new assay in the majority of the tested skin samples down to a minimal sample size of 49 mg dry weight (dw). Water content ranged from 10 to 46% in the plug samples, which had SCCs from 2.1 to 77.7 ng/g dw. Epidermal scrape samples had the highest water content (83–87%) and lower SCCs (0.6–15 ng/g dw), while the skin plates had intermediate water contents (60–66%) and SCCs of 2.6–13.0 ng/g dw. SCC was slightly higher in plugs with lidocaine than without (average values of 41 and 33 ng/g dw, respectively). Substantial within-individual variations in cortisol concentrations are also common in other matrices such as blood and hair. Some important factors behind this variation could be e.g. the animal's sex, age, body condition, reproductive stage, and the body region sampled, as well as season, moulting cycles and water temperature. Clearly, more research into SCCs is required. The findings described here represent the first critical steps towards using epidermal skin cell samples to assess chronic stress levels in cetaceans and the development of a widely applicable health-assessment tool in these species.
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| 2. |
- Bechshoft, Thea, et al.
(författare)
-
Developing a new research tool for use in free-ranging cetaceans : recovering cortisol from harbour porpoise skin
- 2015
-
Ingår i: Conservation Physiology. - : Oxford University Press. - 2051-1434. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- We developed a chemical analytical procedure for sampling, extracting and determining epidermal skin cortisol concentrations (SCCs) in the harbour porpoise (Phocoena phocoena) using gas chromatography–tandem mass spectrometry. In brief, this involved a pressurized liquid extraction with a two-step solid-phase clean-up. A derivatization step was conducted prior to detection. To evaluate the new assay, cortisol was analysed in three different sample types obtained from four harbour porpoises: skin plates, dorsal fin skin plugs (with and without lidocaine) and epidermal scrapes. Skin cortisol concentrations could be measured using the new assay in the majority of the tested skin samples down to a minimal sample size of 49 mg dry weight (dw). Water content ranged from 10 to 46% in the plug samples, which had SCCs from 2.1 to 77.7 ng/g dw. Epidermal scrape samples had the highest water content (83–87%) and lower SCCs (0.6–15 ng/g dw), while the skin plates had intermediate water contents (60–66%) and SCCs of 2.6–13.0 ng/g dw. SCC was slightly higher in plugs with lidocaine than without (average values of 41 and 33 ng/g dw, respectively). Substantial within-individual variations in cortisol concentrations are also common in other matrices such as blood and hair. Some important factors behind this variation could be e.g. the animal's sex, age, body condition, reproductive stage, and the body region sampled, as well as season, moulting cycles and water temperature. Clearly, more research into SCCs is required. The findings described here represent the first critical steps towards using epidermal skin cell samples to assess chronic stress levels in cetaceans and the development of a widely applicable health-assessment tool in these species.
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| 3. |
- Bekoe, Samuel Oppong, et al.
(författare)
-
Detection and quantification of antibiotic residues in urine samples of healthy individuals from rural and urban communities in Ghana using a validated SPE-LC-MS/MS method
- 2020
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Ingår i: SN APPLIED SCIENCES. - 2523-3963. ; 2:11
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Tidskriftsartikel (refereegranskat)abstract
- The role of unregulated and inappropriate dispensing, and use of antibiotics remains significant in the development of antimicrobial resistance in infectious disease endemic regions of developing countries. The exposure to antibiotics from unfamiliar and unsuspecting sources such as drinking water and food, and adulterated herbal medicines remains a cause for concern. A sensitive SPE-LC-MS/MS method was developed and validated for the quantification and qualification of 12 antibiotics, including amoxicillin, clavulanic acid, metronidazole, ampicillin, cefuroxime, tetracycline, ceftriaxone, sulphamethoxazole, trimethoprim, ciprofloxacin, benzylpenicillin, and erythromycin, in the urine of healthy volunteers. The method was linear (r(2) > 0.98) within the concentration range 50-5000 ngmL(-1) for all the analytes. Instrument precision of 8-27% and 4-21% at 100 and 1000 ngmL(-1) levels were demonstrated. High mean recoveries between 71 and 125% with minimal variations were obtained for all compounds in the accuracy study. Limits of detection and quantification ranged between 70.3-271.0 ngmL(-1) and 213-821 ngmL(-1) respectively. The validated method successfully detected and quantified 9 of the 12 analytes, with the exception of clavulanic acid, cefuroxime, and benzylpenicillin. Most of the samples contained one analyte (52, 86.7%), with a handful containing two (7, 11.7%) and three analytes (1, 1.7%). Ciprofloxacin was the modal analyte detected (17, 24.6%), with amoxicillin and trimethoprim recording the average lowest (22.76 x 10(3) ngmL(-1)) and highest concentrations (255.47 x 10(3) ngmL(-1)) respectively. The developed method is a useful tool for non-invasive monitoring of consumption and the irrational use of antibiotics in microbial resistant-prone regions of the world.
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| 4. |
- Bekoe, Samuel Oppong, et al.
(författare)
-
Detection and quantification of antibiotic residues in urine samples of healthy individuals from rural and urban communities in Ghana using a validated SPE-LC-MS/MS method
- 2020
-
Ingår i: SN APPLIED SCIENCES. - : Springer Science and Business Media LLC. - 2523-3963 .- 2523-3971. ; 2:11
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Tidskriftsartikel (refereegranskat)abstract
- The role of unregulated and inappropriate dispensing, and use of antibiotics remains significant in the development of antimicrobial resistance in infectious disease endemic regions of developing countries. The exposure to antibiotics from unfamiliar and unsuspecting sources such as drinking water and food, and adulterated herbal medicines remains a cause for concern. A sensitive SPE-LC-MS/MS method was developed and validated for the quantification and qualification of 12 antibiotics, including amoxicillin, clavulanic acid, metronidazole, ampicillin, cefuroxime, tetracycline, ceftriaxone, sulphamethoxazole, trimethoprim, ciprofloxacin, benzylpenicillin, and erythromycin, in the urine of healthy volunteers. The method was linear (r(2) > 0.98) within the concentration range 50-5000 ngmL(-1) for all the analytes. Instrument precision of 8-27% and 4-21% at 100 and 1000 ngmL(-1) levels were demonstrated. High mean recoveries between 71 and 125% with minimal variations were obtained for all compounds in the accuracy study. Limits of detection and quantification ranged between 70.3-271.0 ngmL(-1) and 213-821 ngmL(-1) respectively. The validated method successfully detected and quantified 9 of the 12 analytes, with the exception of clavulanic acid, cefuroxime, and benzylpenicillin. Most of the samples contained one analyte (52, 86.7%), with a handful containing two (7, 11.7%) and three analytes (1, 1.7%). Ciprofloxacin was the modal analyte detected (17, 24.6%), with amoxicillin and trimethoprim recording the average lowest (22.76 x 10(3) ngmL(-1)) and highest concentrations (255.47 x 10(3) ngmL(-1)) respectively. The developed method is a useful tool for non-invasive monitoring of consumption and the irrational use of antibiotics in microbial resistant-prone regions of the world.
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| 5. |
- Casas, Monica Escolà, et al.
(författare)
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Analytical sample preparation strategies for the determination of antimalarial drugs in human whole blood, plasma and urine
- 2014
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Ingår i: Journal of chromatography. B. - 1570-0232 .- 1873-376X. ; 962, s. 109-131
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Tidskriftsartikel (refereegranskat)abstract
- Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urine, which must be improved in order to advance curing the parasitic disease malaria. A key problem also lies in that pharmacokinetic studies not always are performed in patient groups that may benefit most of the treatment such as children, pregnancy and lower-weight ethnic populations. Here we review the available sample preparation strategies combined with liquid chromatographic (LC) analysis to determine antimalarials in whole blood, plasma and urine published over the last decade. Sample preparation can be done by protein precipitation, solid-phase extraction, liquid-liquid extraction or dilution. After LC separation, the preferred detection tool is tandem mass spectrometry (MS/MS) but other detection methods have been used e.g. UV, fluorescence and electrochemical detection. Major trends for sample preparation of the different groups of antimalarials for each matrix and its detection have been summarized. Finally, the main problems that the researchers have dealt with are highlighted. This information will aid analytical chemists in the development of novel methods for determining existing antimalarials and upcoming new drugs
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| 6. |
- Casas, Monica Escolà, et al.
(författare)
-
Analytical sample preparation strategies for the determination of antimalarial drugs in human whole blood, plasma and urine
- 2014
-
Ingår i: Journal of chromatography. B. - : Elsevier BV. - 1570-0232. ; 962, s. 109-131
-
Tidskriftsartikel (refereegranskat)abstract
- Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urine, which must be improved in order to advance curing the parasitic disease malaria. A key problem also lies in that pharmacokinetic studies not always are performed in patient groups that may benefit most of the treatment such as children, pregnancy and lower-weight ethnic populations. Here we review the available sample preparation strategies combined with liquid chromatographic (LC) analysis to determine antimalarials in whole blood, plasma and urine published over the last decade. Sample preparation can be done by protein precipitation, solid-phase extraction, liquid-liquid extraction or dilution. After LC separation, the preferred detection tool is tandem mass spectrometry (MS/MS) but other detection methods have been used e.g. UV, fluorescence and electrochemical detection. Major trends for sample preparation of the different groups of antimalarials for each matrix and its detection have been summarized. Finally, the main problems that the researchers have dealt with are highlighted. This information will aid analytical chemists in the development of novel methods for determining existing antimalarials and upcoming new drugs
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| 7. |
- Nielsen, Frederik Knud, et al.
(författare)
-
Mixture effects of 3 mechanistically different steroidogenic disruptors (prochloraz, genistein, and ketoconazole) in the H295R cell assay
- 2015
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Ingår i: International journal of toxicology. - 1091-5818 .- 1092-874X. ; 34:6, s. 534-542
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Tidskriftsartikel (refereegranskat)abstract
- Mixture effects of 3 model endocrine disruptors, prochloraz, ketoconazole, and genistein, on steroidogenesis were tested in the adrenocortical H295R cell line. Seven key steroid hormones (pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone, estrone, and 17β-estradiol) were analyzed using gas chromatography and tandem mass spectrometry (GC-MS/MS) to investigate the effects throughout the steroidogenic pathway. Current modeling approaches often rely on models assuming compounds acting independently and that the individual effects in some way can be summarized to predict a mixture effect. In H295R cells with an intact steroidogenic pathway, such assumptions may not be feasible. The purpose of this study was therefore to evaluate whether effects of a mixture with differing modes of action followed or deviated from additivity (concentration addition) and whether the H295R cell line was suitable for evaluating mixture toxicity of endocrine disruptors with different modes of action. The compounds were chosen because they interfere with steroidogenesis in different ways. They all individually decrease the concentrations of the main sex steroids downstream but exert different effects upstream in the steroidogenic pathway. Throughout the study, we observed lowest observed effect concentrations of mixtures at levels 2 to 10 times higher than the predicted EC50, strongly indicating antagonistic effects. The results demonstrate that chemical analysis combined with the H295R cell assay is a useful tool also for studying how mixtures of endocrine disruptors with differing modes of action interfere with the steroidogenic pathway and that existing models like concentration addition are insufficient in such cases. Furthermore, for end points where compounds exert opposite effects, no relevant models are available.
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| 8. |
- Nielsen, Frederik Knud, et al.
(författare)
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Mixture effects of 3 mechanistically different steroidogenic disruptors (prochloraz, genistein, and ketoconazole) in the H295R cell assay
- 2015
-
Ingår i: International Journal of Toxicology. - : SAGE Publications Inc.. - 1091-5818 .- 1092-874X. ; 34:6, s. 534-542
-
Tidskriftsartikel (refereegranskat)abstract
- Mixture effects of 3 model endocrine disruptors, prochloraz, ketoconazole, and genistein, on steroidogenesis were tested in the adrenocortical H295R cell line. Seven key steroid hormones (pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone, estrone, and 17β-estradiol) were analyzed using gas chromatography and tandem mass spectrometry (GC-MS/MS) to investigate the effects throughout the steroidogenic pathway. Current modeling approaches often rely on models assuming compounds acting independently and that the individual effects in some way can be summarized to predict a mixture effect. In H295R cells with an intact steroidogenic pathway, such assumptions may not be feasible. The purpose of this study was therefore to evaluate whether effects of a mixture with differing modes of action followed or deviated from additivity (concentration addition) and whether the H295R cell line was suitable for evaluating mixture toxicity of endocrine disruptors with different modes of action. Thecompounds were chosen because they interfere with steroidogenesis in different ways. They all individually decrease the concentrations of the main sex steroids downstream but exert different effects upstream in the steroidogenic pathway. Throughout the study, we observed lowest observed effect concentrations of mixtures at levels 2 to 10 times higher than the predicted EC50, strongly indicating antagonistic effects. The results demonstrate that chemical analysis combined with the H295R cell assay is a useful tool also for studying how mixtures of endocrine disruptors with differing modes of action interfere with the steroidogenic pathway and that existing models like concentration addition are insufficient in such cases. Furthermore, for end points where compounds exert opposite effects, no relevant models are available.
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| 9. |
- Oppong Bekoe, Samuel, et al.
(författare)
-
Determination of thirteen antibiotics in drug products : a new LC-MS/MS tool for screening drug product quality
- 2014
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Ingår i: Analytical Methods. - 1759-9660 .- 1759-9679. ; 6, s. 5847-5855
-
Tidskriftsartikel (refereegranskat)abstract
- Poor quality antibiotic medicines in circulation in Sub-Saharan Africa continue to be a burden. Pharmaceutical trade in substandard and counterfeit medicines is on the rise. The chemical quality of antibiotics dispensed in health facilities and recognised drug outlets in Ghana, when compromised, could be a major drawback to efforts made in fighting antibiotic resistance globally. To improve on antibiotic drug quality monitoring, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology, which is capable of quantifying thirteen antibiotics in drug products, was developed and validated in present work. The methodology was applied to various drug products including tablets, capsules, suspensions, syrups, intravenous and injection solutions as well as ear and eye droplets used as essential medicines in a Sub-Saharan country, Ghana.
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| 10. |
- Oppong Bekoe, Samuel, et al.
(författare)
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Determination of thirteen antibiotics in drug products : a new LC-MS/MS tool for screening drug product quality
- 2014
-
Ingår i: Analytical Methods. - : Royal Society of Chemistry. - 1759-9660 .- 1759-9679. ; 6, s. 5847-5855
-
Tidskriftsartikel (refereegranskat)abstract
- Poor quality antibiotic medicines in circulation in Sub-Saharan Africa continue to be a burden. Pharmaceutical trade in substandard and counterfeit medicines is on the rise. The chemical quality of antibiotics dispensed in health facilities and recognised drug outlets in Ghana, when compromised, could be a major drawback to efforts made in fighting antibiotic resistance globally. To improve on antibiotic drug quality monitoring, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology, which is capable of quantifying thirteen antibiotics in drug products, was developed and validated in present work. The methodology was applied to various drug products including tablets, capsules, suspensions, syrups, intravenous and injection solutions as well as ear and eye droplets used as essential medicines in a Sub-Saharan country, Ghana.
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